1. Field of the Invention
The present invention relates to a supporting structure to be used as an atmospheric-pressure-resistant means of a vacuum container in a flat-type display apparatus which is constructed using an electron-emitting device, and to a method of manufacturing the same. The present invention further relates to a display apparatus which is constructed using the supporting structure.
2. Related Background Art
Generally speaking, in a display apparatus in which a first substrate, which is an electron source substrate equipped with a plurality of electron-emitting devices, and a second substrate are opposed to each other with a space therebetween, a supporting structure (spacer) formed of an insulating material is held between the first substrate and the second substrate in order to attain the requisite resistance to the atmospheric pressure.
In a known method of manufacturing such a supporting structure, a glass base material is subjected to heat drawing and is cut to a predetermined length by a diamond cutter or through laser beam irradiation (Japanese Patent Application Laid-open No. 2000-251705). Further, as is known in the art, it is possible to prevent charging of a supporting structure by providing a plurality of grooves in the surface of the supporting structure. Also as a method of manufacturing a supporting structure with a plurality of grooves in the surface thereof, a method is known in which a glass base material is subjected to heat drawing and is cut to a predetermined length by a diamond cutter or through laser beam irradiation (Japanese Patent Application Laid-open No. 2003-229056). The known method, however, has a problem in that stress is concentrated on minute protrusions and chips, generated in the section in the cutting process, resulting in buckling destruction of the supporting structure; further, due to concentration of an electric field on such protrusions and chips, surface discharge is likely to occur.
In view of this, Japanese Patent Application Laid-open No. 2000-251705 discloses a manufacturing method according to which smoothing of the section obtained through cutting is effected by performing heating or chemical etching processing on the supporting structure after the cutting, thereby preventing buckling destruction and surface discharge of the supporting structure.
However, when a supporting structure with grooves formed in the surface thereof for charging prevention is to be manufactured, the manufacturing method as disclosed in Japanese Patent Application Laid-open No. 2000-251705 involves a change in the configuration of the grooves (the depth, angle, and ridge portion configuration thereof) due to annealing and chemical etching, so that it is impossible to achieve a desired charging prevention effect.